Imagine a healthy forest. There is life from soil to sky, and it is diverse and abundant. This is more than a collection of trees and shrubs, it is an ecosystem: a biological community interacting with itself and its environment as a system. Most notably, human involvement is absent. This ecosystem is self-sustaining. Permaculture attempts to replicate this model, or its patterns, in the [eco]systems it designs, like a food forest, for example. The net result when successful is a self-sustaining system that provides a yield beneficial to humans. In short, permaculture is a design system based on patterns found in nature. 
 

Alex Wolf